As of Friday afternoon, the Currowan bushfire is at watch and act alert level.

Rural Fire Service has told holidaymakers to leave the area, and those residents who can not physically or mentally prepare and defend their home should leave on Friday.

Weather conditions will be hot, dry with strong north-westerly winds on Saturday. A total fire ban is in place as well as a state of emergency.

Shoalhaven RFS district manager, Superintendent Mark Williams, said the Currowan fire could move through Ulladulla in the south, inland through Wandandian and through several coastal villages.

"Lake Conjola, Bendalong, Cunjurong Point, Sussex Inlet, Vincentia, St Georges Basin, Basin View, up to and including Huskisson, back out to Falls Creek and Tomerong areas could be impacted by fire," he said.

"Huskisson probably won't be under threat from the Currowan fire but more likely from the Comberton blaze. That fire is being watched and is contained but it could jump out of its box, and under north-westerly conditions, it could run towards Huskisson."

Supt Williams said the other big concern was fire jumping the Shoalhaven River, taking hold and running towards Kangaroo Valley.

RFS was reporting the fire had jumped the river around 12pm.

"There are very dynamic fire conditions," Supt Williams said.

"The fire is coming across in 'fingers' from the west to the east. It is so spread out and there is a lot of unburnt pockets of land."

The perimetre of the fire is more than 1000 kilometres, just in the Shoalhaven area.

Supt Williams said there is about 30 to 40 per cent of active fire.

That is predominately between Ulladulla, Wandandian, and outskirts of Basin View, leading up to North Nowra.

"There is a very real likelihood that with the conditions on Saturday, those areas of land and urban interface in coastal villages could come under impact," he said.

"Any of those fire edges are our concern on Saturday under north-westerly conditions.

"We have tried to put containment lines in known areas the fires can travel, however, there is a lot of uncontained fire.

"We are expecting the fire to develop very quickly on Saturday and move fairly significantly throughout the landscape."

Supt Williams said in the past three days, fire crews had been investigating where the fire ran to when it swept through Conjola Park on New Year's Eve.

"On Friday, the management team are trying to work out containment options for crews to get in and provide some protection to communities around the coast before Saturday's expected bad weather," he said.

Crews worked hard on Thursday to carry out backburning operations.

"Thursday saw us very busy in undertaking an eight kilometre stretch of backburning along the Princes Highway, which was done in record time," Supt Williams said.

"We eventually got the highway re-opened at 4.30am on Friday morning."